As a technique for remotely controlling an electronic device with accuracy even from a remote location, a communication system as described in PTL 1 is known. In the communication system described in PTL 1, a portable terminal operated by a user, a database, a video recorder and a base station communicate with one another via a network. In the database, as information required for a VTR (Videotape Recorder) to make a recording reservation, a program guide is recorded, which includes, for example, broadcast channels, broadcast starting times and the like of broadcast programs. The portable terminal of the user communicates with the database via the base station and the network, to receive the program guide from the database and display the program guide. The user refers to the program guide, and confirms a broadcast channel, broadcast starting time and the like of a program to be subjected to the recording reservation. Then, the user issues an instruction on the program to be subjected to the recording reservation to the portable terminal. Information on the program on which the instruction is issued by the user is transmitted from the portable terminal via the base station and the network to the VTR. In this manner, the VTR executes the recording reservation based on the received information on the program. As described above, the user can allow the VTR to make the recording reservation by using the portable terminal from any location as long as the location is in an environment where the portable terminal connects to the network.
Moreover, in NPL 1, there is disclosed a technique in which two terminals belonging to different networks perform communication by the Peer to Peer connection that does not pass via a server. In this manner, a load on the server can be reduced. Note that the “Peer to Peer” is hereinafter referred to as “P2P”.